ANSWERS:

ROUND 3 (Drug Quotations, you name the person who said it):

1) "Turn on, tune in, drop out." TIMOTHY LEARY
2) "You see, I think drugs have done some good things for us. I really do. And if you don't believe drugs have done good things for us, do me a favor. Go home tonight. Take all your albums, all your tapes and all your CDs and burn them. 'Cause you know what, the musicians that made all that great music that's enhanced your lives throughout the years were rrreal fucking high on drugs." BILL HICKS
3) (Commenting on the song 'One Toke Over the Line' playing on the radio) "One toke? You poor fool! Wait till you see those goddamn bats." (I GOT THIS! Despite never having seen the movie). They wanted the movie: FEAR AND LOATHING IN LAS VEGAS
4) Can't remember, didn't write down.
5) "Just Say No" NANCY REAGAN
6) "To Alcohol! The cause of--and solution to--all life's problems." HOMER SIMPSON

Round 5 (Tell me how they died):

1) Michael Hutchins (INXS) AUTO EROTIC ASPHYXIATION
2) Cliff Burton (Metallica) BUS CRASH
3) Ian Curtis (Joy Division) DEATH BY HANGING
4) Joe Strummer (The Clash) UNDIAGNOSED CONGENITAL HEART DEFECT
5) Sonny Bono SKIING ACCIDENT (TREE)
6) Marvin Gaye SHOT BY FATHER